package cn.tedu.sp06.fallback;

import cn.tedu.sp01.Util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * 通过zuul网关，调用后台商品服务失败时，
 * 会执行这段降级代码，向客户端返回降级结果
 */
@Component
public class OrderFB implements FallbackProvider {
    /**
     * 设置当前降级类，针对哪个服务的降级类
     * -item-service 只针对商品服务降级
     * *: 针对所有服务都应用当前降级类
     *
     * @return
     */
    @Override
    public String getRoute() {
        return "order-service";
    }

    /**
     * 发送给客户端的降级结果，封装在responce对象中
     * @param route
     * @param cause
     * @return
     */
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            /**
             * getStatusCode
             * 状态码
             * 状态文本
             * @return
             * @throws IOException
             */
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;//{code:500,text:服务器内部错}
            }


            /**
             * 状态码
             * @return
             * @throws IOException
             */
            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();// 500
            }

            /**
             * 状态文本
             * @return
             * @throws IOException
             */
            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();//"服务器内部出错"
            }

            @Override
            public void close() {
                //用来关闭流
                //ByteArrayInputStream 不需要关的
            }

            @Override
            public InputStream getBody() throws IOException {
                //JsonResult
                String json = JsonResult.err().code(500).msg("调用订单服务失败").toString();
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {
                //content-type: application/json;charset=utf8
                HttpHeaders h = new HttpHeaders();
                h.add("Content-Type", "application/json;charset=UTF-8");
                return h;
            }
        };
    }
}
